Will a 15 inch wheel clear the GM front break swap

[MonsterBIlly]

I have a wheel for a spare, I just want to make sure it clears the gm caliper

 

[Digger556]

I have a wheel for a spare, I just want to make sure it clears the gm caliper

I ran 15" steelies with GM calipers. You may want to fit yours up, not all rims have the same interior geometry.

 

[904Bronco]

Well I am going to say yes, but...

Depends on rim, how it is constructed, maybe the back spacing too...

 

[Broncobowsher]

In general, yes. 15" where were used from the factory with GM brakes. You just have a different rotor with a different bolt pattern.

But there are exceptions. Some of the early 15" wheels didn't have a need to clear disk brakes. So they were not sculpted for clearance. Ford was running disk brakes as early as '73 on the 2WD F150, same wheel fits everything. And the aftermarket trys to make one wheel fit as many applications as possible. This leaves the early factory wheels ass the ones that are usually the problem child. And even then they may clear.

This isn't just the GM brakes. If the wheel doesn't clear the GM brakes, it probably isn't going to clear the Ford or the aftermarket either. Time for another wheel.

 

[Glass Pony]

I have a wheel for a spare, I just want to make sure it clears the gm caliper

There's only one way to be sure.

 

[abn373]

I have used both 15in steel wagon wheels and currently 15" Mickey Thompson Classic in aluminum and never had any issue with the GM disc conversion.

 

[McLeod]

I have a set of late 70's aluminum 15" wheels that clear the GM discs but won't clear the Ford discs.

Gotta try them out to be sure.

 

[Broncobowsher]

I have a set of late 70's aluminum 15" wheels that clear the GM discs but won't clear the Ford discs.

Gotta try them out to be sure.

The actual caliper or is it they won't clear the relocated tie rod end of the knuckle?

The tie rod end interference is rather well known but gets better if you use F150 knuckles instead of Bronco knuckles. But if it is caliper interference I guess that makes the GM brake package a little more compact.

 

[McLeod]

Well, let me back up a bit for clarification.
This may or may not be apples to oranges, but more of a "check to verify -vs- assume they work"

The wheels I have are 1977 Keystone Turbos in 15 x10, 3.75 back spacing, which was in a year that most if not all of the trucks had disc brakes as new.

Those wheels DO clear the GM disc conversion I have.
Now as to what Ford brake set up they DO NOT clear on is the 80's up FORD set up.
I don't have a 76-79 set up to test it out on

The clearance issue was the caliper body itself and not the tie rod.
The wheel would go on, but would slightly contact in caliper area and drag and would have worn a slight groove in the main wheel hoop.

Given that, Even though the fitment interference may not apply to 76-79 I would not assume that all EARLY disc brake wheels were the same. I would attempt to verify before buying early disc wheels.

 

[Broncobowsher]

That's interesting. I would have thought it was the tie rod. But now that you mention it I remember the Red Racer had the wheels chucked in a lathe to remove a little material on the inside of the wheel for caliper clearance. Knowing Todd, I am sure he did a thickness check before and after the machine work.

 

[toddz69]

That's interesting. I would have thought it was the tie rod. But now that you mention it I remember the Red Racer had the wheels chucked in a lathe to remove a little material on the inside of the wheel for caliper clearance. Knowing Todd, I am sure he did a thickness check before and after the machine work.

I did do a thickness check back in the day when we removed some material - Red Racer has Dodge calipers as part of the Hickey disc conversion. The OG slots do not clear disc brake calipers.

In fact, Parnelli had the same problems with Big Oly in one of the Baja races when someone put the wrong slots on it.

Todd Z.

 

[Broncobowsher]

Didn't know it was running Dodge parts. I take it this isn't the 13" rotor that you were working on a few years back? Just old school Dodge stuff? Isn't there a camber issue running Dodge stuff on a Ford axle due to a different SAI angle?

Sorry, looks like I am hijacking this thread.

 

[toddz69]

Didn't know it was running Dodge parts. I take it this isn't the 13" rotor that you were working on a few years back? Just old school Dodge stuff? Isn't there a camber issue running Dodge stuff on a Ford axle due to a different SAI angle?

Sorry, looks like I am hijacking this thread.

Yeah, different deal. These are late '60s/early '70s Dodge car calipers on Hickey brackets. The first EB disc conversion that I'm aware of. Stock knuckles so SAI is unaffected.

Todd Z.

 

[rguest3]

Mount up the spare. See if it clears.